How do i connect to the internet in backtrack?

my laptop runs on windows but i have backtrack 3 and 4 on live cd's.when i reboot into backtrack my built-in wireless card (atheros ar9285) wont work.ive been told i need to download the ath9k driver but i cant access the internet in backtrack.i know the BASIC linux commands but dont know how to connect to my router(in backtarck) with an ethernet cable so i can download the driver.can anyone help PLEASE:)